The metal-catalyzed hydrolytic cleavage of RNA is fundamental to the chemistry of gene expression. For example, the maturation and degradation of RNA are carried out by ribonucleases and ribozymes in processes that nearly always require metal cofactors. However, the detailed chemical role or roles of the metals remain largely unknown. We intend to unravel the role of metal ions in these reactions and utilize this mechanistic information to design a series of synthetic ribozymes. In parallel with our mechanistic studies, we are employing a variant of the synthetic analoque approach in which functional mimics of RNA enzymes are designed and prepared. Here, we are developing synthetic ribozymes derived from hydrolytically active metal complexes. Mass spectrometry is used for characterizing these materials.